newInstance

getQueryString

Return the query string ("select * from bla")
NOTE: Might want to be overridden by indiviual EsqlQuery implementations
e.g. for database specific LIMIT features. Be aware that there a two different
limit approaches:

With the "retrieve time" limit the JDBC ResultSet includes ALL of the rows of the
query.
With the "query time" limit only a small window of rows are in the actuall JDBC
ResultSet. In order to know whether there are more rows available (without an additional
query) we need to have at least one more row in the JDBC ResultSet. So we ask for getMaxRows()+1